Chair iron



T. ELLEMAN CHAIR IRON 2 Sheets-Sheet 1 Filed Jan. 5, 1945 Feb. 21, 1950 T ELLEMAN CHAIR IRON 2 Sheets-Sheet 2 Filed Jan. 5, 1945 I llll|ll I III] INVENTOR. ram Elli/ 719M ATTUE/VEP:

l atented Feb. 21, 1950 CHAIR IRON Tom Elleman, Port Washington, Wis., assignor, by mesne assignments, to The Seng Company, Chicago, 111., a corporation of Illinois Application January 5, 1945, Serial No. 571,377

8 Claims.

This invention relates to improvements in chair irons generally and particularly of the type in which the tilting of the back and the seat are synchronized.

After chair irons have been in use for a period of time, certain changes in the metallurgical structure of the spring tensioning rod often take place permitting the rod to break when placed under tension or when the seat is tilted with a jolt. When this occurs, the spring and part of the rod is projected from under the chair with sufficient force to injure an occupant of the chair or any other person within the immediate range.

One of the objects of this invention, therefore, is to provide a chair iron in which the compression spring is held adjustably in such a way that it andits adjusting rod cannot be projected from under the chair if any breakage occurs.

Another object of the invention is to provide a chair iron in which the working parts are protected so that oil or other lubricants used thereon will be caught and restrained from dropping on floors and floor coverings while the chair is in use.

Another object of the invention is to provide a chair iron which has an easily operated back adjustment mechanism of simple construction.

A still further object of the invention is to provide a chair iron so designed that it may be readily constructed of formed sheet metal parts thereby eliminating the necessity of castings.

The foregoing objects are accomplished by providing a head piece in the form of a housing open at the top having a bottom, opposite side walls, a front wall, and a low back wall. A coiled compression spring is mounted and enclosed within the housing. An adjustable screw, threadedly carried in the forward wall of the housing, bears against the forward spring-retaining cup. A lever mechanism is also pivotally mounted in the housing adjacent the back wall and has one arm in abutting relationship with a spring-retaining cup on the rear end of the spring and movable toward the forward wall as the seat is depressed,

and another arm operatively connected to a spider which itself is pivoted to the housing which forms the head piece. As the seat which is car-' the lever mechanisms and the fulcrum bearings between the spring and the mechanism, all of which parts must be freely lubricated, are all contained within the housing, and any excess lubrication which drops from these hearings will be caught by the bottom wall of the housing and will not fall on the floor or floor coverings.

The back-supporting sub-assembly is carried by the spider and operated under the control of the lever mechanism described in the previous paragraph. It comprises a main carrying plate to which a back-supporting bracket is pivotally mounted and angularly adjustable relative thereto. This adjustment is accomplished by the manual operation of an adjusting hand wheel mounted on a rod having a ball and socket joint connection with the back-supporting bracket and threadedly contained in a rotatable trunnion carried by the main carrying plate. The rotation of the hand wheel causes the rod to move longitudinally relative to the trunnion which results in angularly moving the back-supporting bracket about its pivot. The changing angular relationship between the rod and the back-supporting bracket is readily accommodated by the ball and socket connection, and the changing angular relation between the rod and the main carrying plate is accommodated by the rotation of the trunnion. Thus this adjustment is readily handled by a simple mechanism.

With the foregoing and other objects in view, developed by the following description, the invention consists in certain novel advantageous structural organizations and features, as well as combinations and sub-combinations, as more fully explained hereinafter and specified in the following claims.

Referring to the accompanying drawings forming a part hereof,

Figure 1 is a sectional view through a chair iron embodying the invention and diagrammatically showing the support for the chair back;

Figure 2 is a top plan view of the chair iron of Figure 1 with the seat removed and with certain of the parts broken. away for the sake of clarity in illustration;

Figure 3 is a view in front elevation of the chair iron of Figure 1 (front elevation means viewing the chair iron from the front of the seat); and

Figure 4 is a fragmentary sectional view taken on the line 4-4 of Figure 1.

Referring in greater detail to the drawings, the chair iron is mounted on a base (not shown) of standard design in which is supported a hub seat S (shown diagrammatically).

H]. A vertically adjustable spindle I I is rotatably carried in the hub Ill. The vertical adjustment of the spindle is controlled by a nut 12 threadedly mounted on the spindle. The nut l2 bears against the top of the hub l0, and a ball bearing assembly 13 is interposed therebetween to receive the thrust with a minimum of turning friction. A holding screw I4, carried in a downward projection on the nut, engages in a groove formed in the hub It) to prevent the spindle and nut assembly :from being Withdrawn vertically from the hub. In order to give the nut a pleasing appearance and to afford a ready grip for rotating the nut on the spindle, it is provided with a downwardlydepending skirt l5. The skirt 15 has an aperture iii through which the screw 16 may be reached in the event it is required to remove the spindle and nut from the hub.

A head piece designated generally at 20 is mounted on the upper end of the spindle l I. The head piece 28 is in the shapeof a housing --ivhidh can be formed from sheet metal. The heus'ing is open at the topand has a bottom 21, a iro'rit wall 22,- side walls 23, and a-low back wall 24. The opening defined by the front wall, side walls',-arid rear wall has a-small marginal outwardly-extending flange extending substantially therearound. This adds to the structural strength of the housing and enhances its appearance. The top edges of the side walls slope gradually from thejfront wall to a point substantially one-third of the length of the housing from the rear. From this point on back to the rear wall 24, the side walls slope downwardly at a substantial angle to provide space for the tilting of" the spider.

H The head piece 28 is mounted on the spindle l i. To effectuate such mounting the top of the spindle is provided with a taper. A bearing member 25 provided with an annular flange is inserted in an aperture formed in the bottom 2! so that the flange rests flatly against the bottom and may be spot-welded thereto. The bearing member 26 has a neck portion which protrudes upwardly within the head iece. This bearing member has a central tapered bore which fits snugly with the taperedtop of the spindle H. To further brace the juncture between the head piece and the spindle, a saddle-member 2! (shown in detail in Figure 4) is provided within'the head piece 20. It is substantially U-shaped in cross section, but the central portion'of its bottom is formed upwardiy to fit over the top of the neck of the bearing member 28. In making this upward formation, a flat portion 28 is provided on the forward side, and a flat sloping portion 28 is provided on the rearward side to act as abutments for the lever mechanism. The saddle 2! is inserted in place so that its legs lie closely against the inner sides 23 of the head piece 20 and the top of its upwardly-formed central portion rests snugly on the top'of the bearing member 25. It is then welded or otherwise secured in place. The saddle member 21 has an aperture to receive the upward tapered end of the spindle gather. It should be noted that the spindle I l is *securedto the head piece 28 near its rear edge.

This afiords space for the compression spring and also'permits the'pivot for the chair spider to be positioned adjacent the forward edge of the chair It will be notedlas shown in Figure 3) that the bottom of'the headpiece 20 is narrower tha'n its opening. The side walls of the head piece therefore converge downwardly. To provide vertical flat faces for the two bearings mounted on the head piece, two outwardly-pressed portions 3! are provided at the top forward edge of the head piece, and two outwardly-pressed portions 32 are provided at approximately the central top portion of the head piece. The flattened portions 31 have apertures which tightly receive and hold a tubular member 33 which spans the head piece from the outer surfaces of the respective fiat portions. Bushings 34 are contained within the tubular member 33 at its ends. These bushings are adapted to rotatably receive and hold the rod--35 upon which the spider is mounted.

A bell crank designated generally at 49 is pivo'tally mounted in the head piece 20. It is formed from two sheets of metal of identical outline configuration which are secured together by spotwelding or otherwise suitably fastened. The forward arms 4| asillustrate'd in Figure '2, are bent laterally out 'to space each arm as indicated. These arms have apertures which tightly receive and hold the tubular bearing member. Bushings A5 are fixedly positioned within the-ends of the bearing m'e'mbe'r 42. Another tubular bearing member 43 is rotatably' carried withinthe bearing member -42 by thesebus-hings. This member-extends between the inner surfaces of the flats'32 and is held in place by a rod M, which has its ends riveted against the outersurfac'esoi' the flats 32. Thus the member 43' acts-as a spacer and brace for the housing,-'aswell as a'piv'otal be'aring for the lever mechanism. The'length oi the tubular member '42 is just a little bit less than the distance between the inner su'rfa'ces of the flats 32,'thus permitting it to'readily'rotatewhile preventing any great axial movement thereof. The rearward arm 46 of the bell crank has, at its lower end, out-turned ears 4! which form a fiat carrying surface for a resilient pad. This pad abuts against the rear flat 29 to limit the movement of the bell crank in a counterclockwise direction, as viewed in Figure -1. The rearward arm efi'is apertured to tightlyreceive and holda tubularmember "49 which has at-its ends bushings (not numbered) adapted torotatably receive a bearing pin '84 which is mounted on the back-supporting sub-assembly. The lower or spring arm 59 of 'thebell crankdil also has extending ears 5| which carry a resilientpad 52 which abuts against the forwardflat wall28 to limit the movement of the-bell crank'in a clockwise direction. This arm 'alsohas'a'forwardlyprojecting knob '53 whichacts as'a fulcrum for the rear spring-retaining cu 54.

The method of adjustably-mounting the coiled compression spring "64 isunique. The forward wall 22 ofth'ehou'singifl is rovided with anaperture inwhi'c'h is inserted'and swaged in place a threaded nut so. Thenut'is soshaped thatit cannot beforced outwardlythrough'the opening under the maximum force which can be "exerted by the movement of'the chair seat relative to the head piece. This nut threadedly carries a springadjusting screw "6| which has a portion extending within the headpiece 2i and provided-with a ball'bearing cnd'62 fitting in the spring-retaining cup 63. Thecoiled compression-spring'lil is carried between the retaining cups 5 3 and 63 and is placed under compression'by the adjustment of" the screw'fi l to continually urge'the'bell crank 40 in aclockwisedirection-about its pivotal mounting 44. 'A portion of the rodBl projects' outside the housin 26 and-is providedWith a hand wheel 85 whereby it may be easily rotated to adjust the tension on the spring 54.

The chair spider, upon which is mounted the chair seat diagrammatically shown and designated S, is formed of two oppositely-positioned angle irons 18 which are held in spaced relationship by a pair of cross brackets 'H' extending across the top thereof and spot-welded or otherwise securely held thereto. The to legs of the angle brackets have apertures through which screws may be inserted into the wood portion of the chair seat S to secure it to the spider. As previously described, a rod 35 extends between the lower legs of the angle irons 10 at their for- Ward ends and is rotatably held within the bushings 33, to pivotally mount the spider to the housing. In order to space the spider from the outer walls of the housing, spacing washers 12 are inserted on the rod 35 between the outer surfaces of flats 3| and the vertical legs of the angle irons.

From the foregoing description, it will be seen that by a force transmitting connection provided between the rear arm 46 of the bell crank 40 and the spider, any pressure on the seat S tending to depress it about the pivot 35 will cause the bell crank 40 to rotate about its pivotal connection 44. When, as viewed in Figure 1, this movement causes a counter-clockwise rotation of the bell crank, the lower or spring arm 58 moves toward the front wall 22 and the spring 64 is placed under additional compression and resiliently resists such movement. If any breakage should occur on that portion of the adjusting screw 6| within the housing 20, the spring would not be catapulted so as to cause damage. Instead it and the broken part of the screw Bl, would be contained within the housing. In addition, lubrication placed on the knob 53, ball bearings 62, bushings 45, and bearing 49, if excessive, would be caught by the bottom 2!, preventing damage to expensive floor coverings.

In the application of Alexander J. Raitch, Serial No. 491,576, now Patent No. 2,441,251, granted May 11, 1948, assigned to the assignee of this application, there is shown, described in detail, and also claimed a back-supporting subassembly which, through the action of a bell crank (like 48), is angularly moved relative to the seat as the seat is tilted. Reference may be made to this application for the details of construction and method of operation. The backsupporting sub-assembly designated generally at 80 functions in substantially the same way as does that of the foregoing application. It also provides the force transmitting connection between the rear arm 46 and the spider. It differs only in the method of construction and in the improved method of regulating the initial angular relationship of the back to the seat. It is formed of a main carrier plate 8| which has depending legs 82. The forward ends of these legs are pivotally mounted on the rod 73 carried by the spider by a bearing assembly identical in construction with that previously described and by which the rod 35 is pivotally mounted to the housing 28. Spaced inwardly from the legs 82 and projecting downwardly from the carrying plate 8| to which it is rigidly secured is an inverted U-shaped bracket member 83. This member 83 at its forward end has oppositely-related apertures in its legs which fixedly receive the bearing pin 84. This pin 84, as heretofore described, is rotatably mounted in the tubular member 48 of the bell crank 40. When bell crank 40 is moved counter-clockwise about pivot 44, the pivotal connection 49 also moves downwardly in the arc of a circle of which the rod 44 is the center, and the pivotal connection 13 moves in the arc of a circle of which the rod 35 is the center. Thus the carrier plate 8|, the bracket member 83, and the back-carrying bracket 85 will be caused to rotate as a unit in a counter-clockwise direction about the pivotal connection 13 as the seat S and spider are depressed from the position shown in Figure 1. This causes the whole sub-assembly to widen its angular relationship to the seat S, and the back-carrying member B will be articulated relative to the seat S while it is being depressed, as is fully shown and described in the Raitch application above identified.

In order to initially adjust the relative angularity between the back-carrying member B and the seat S to fit the needs of a particular occupant of the chair, the back-supporting sub-assembly also consists of a back-supporting bracket of customary design which is pivoted by the oppositely-related aligned rivets 86 to the opposite legs 82 of the carrying plate 8|. To alter the angular adjustment of the back-carrying bracket 85 relative to the main carrying plate 8|, the bracket 83 has its depending legs at the rearward end provided with apertures in which is rotatably mounted a trunnion 81. A threaded aperture passes through the trunnion perpendicularly to its longitudinal axis. This aperture threadedly receives an adjusting screw 88 provided with a hand wheel 89. The outer end of the screw 88 is provided with a ball which is one of the elements of a ball and socket joint indicated generally at by which the screw 88 is universally connected to the lower end of the bracket 85. Upon the rotation of the screw 88, the back-carrying bracket 85 is caused to rotate about the pivot 86, thus adjusting its angular position relative to the back-supporting sub-assembly as a whole. As this angular relationship is changed, the angle between the screw and the bracket 83 is consequently altered, which motion is permitted and provided for by the rotation of trunnion 81. In the assembly of this part of the structure, the ball and socket joint 90 and screw 88 are first assembled to the bracket 85 and after it has been pivotally riveted to the carrying plate 8!, the trunnion 81 may be inserted axially through the openings in the bracket 83. After the screw 88 is threadedly inserted in the trunnion, it holds the trunnion in place, and no other elements are necessary to keep the trunnion from sliding out of position.

Although there is shown and described certain specific embodiments of the invention, many modifications thereof are possible. The invention is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

I claim:

1. In a chair iron, a head piece having walls and a bottom, an adjustable member carried by one of said walls, a compression spring positioned within the enclosure defined by said walls and bottom and having one end engageable with said adjustable member, a bell crank mounted in said head piece and having an arm in abutting relaform of a housing having a bottom, front, and

side walls, and arim forming a low rear-wall, said bottom wall having a bearing member adapted to receive said spindle, a saddle positioned in said head piece and cooperating with said bearing member and said walls tobrace said bearing mem ber, adjustable means carried by one of said walls, a resilient compressive member positioned within the confines of said walls and abuttingat one end against said adjusting means, abell crank carried by said side walls and having a portion in abutting relation :to the other end of said compressive member and movable toward said wall carrying said adjustable means to compress said compressive member, a spider pivoted to said head piece, and means operatively associating said bell crank and said spider whereby the force of said compression member is transmitted to said spider.

3. A chair iron comprising a spindle adapted to be mounted on a pedestal, a head piece formed from sheet metal having a bottom, front, and side walls, and a rim forming a low rear wall, said bottom having an aperture therein, a bearing member for said spindle mounted in said aperture, a sheet metal saddle rigidly-mounteddvithin said side Walls and having its bottom portion formed upwardly to engage with andbrace said bearing member, a nut rigidly held in one of said walls, a screw threadedly mounted in said nut and having an end portion within the confines of said walls, a lever having a rear arm and a spring-engaging arm pivoted between said side walls, said arms having cushioning pads mounted thereon and adapted :to engage with portions of said saddle to limit the pivotallmovement of said lever, a resilient member mounted within the confines of said walls and. having one end engaged with the end portion of said screw and the other end engaged with said springarm, a spider pivotally mounted on said side walls, and means operatively connecting said spider and said rear arm whereby turning force exerted on said spider is resiliently resisted by said resilient member.

4. A chair seat comprising a spindle, a head piece mounted on said spindle, a chair seat spider pivoted to said head piece, a back-supporting subassembly pivoted to said spider, a bellcrankcarried by said head piece and operable to pivot said back-supporting sub-assembly upon the tilting of said spider relative to said head piece, re-

silient means operably associated with said bell crank to resiliently urge it in one direction, said back-supporting sub-assembly comprising a main carrying plate member, a back-supporting bracket member pivoted thereto, and an adjustable screw member universally rotatively connected to one of said members and threadedly engaged with a trunnion carried by the other of said members and rotatable about an axis disposed normally to the longitudinal axis of, said screw member.

5. A back-supporting sub-assembly pivotally mounted to have angular movement as a unit relative to the chair seat spider upon motion of said chairseat-spider comprising, a main carrying plate adapted to be pivotallymounted to the spider, a back-supporting bracket pivotally lar to the axis of rotation of said trunnion, and a ball ,and ,socket connection between said screw and said back-carrying bracket whereby the rotation of said screw adjusts the initial angular relationship between said bracket and said main carrying plate.

6. In a chair iron having a pivotally mounted spider, a head piece comprising a housing having side walls, a front wall and a bottom, a bell crank mounted within said housing, bearing means for mounting said bell crank including a rigidly fixed tubular member extending between the inner surfaces of the oppositely related walls of said housing to properly space and bracesaid walls and movable means rotatably mounted on said tubular member, a resilient member positioned in spaced relation to said side walls, and ,positioned between said'bell crank and said front wall so as to be compressible therebetween, and means operatively associating said spider and said bell crank, the bearing means for mounting said bell crank and the connections of said resilient member being positioned within the confinesoi said bottom whereby excess lubrication will be collected by said bottom.

7. :In ,a chair iron, a head piece having a wall, a spider pivoted to said head piece, a bell crank operably connected with said spider and pivoted to said head piece, said bell crank having one of its arms movable toward said wall when the spider isswungdownwardlmand a resilient compressive member positioned between said arm of said bell crank and the wall to resiliently. resist pivoting of said spider.

8. In a chair iron, a head piece having-a front wall and side walls, a resilient compressive member having one end carried by one wall of said head piece and positioned within the confines of said walls, a bell crank pivotally carried by said head piece and having one of its arms bearing against the other end of the compression member and movable toward oneof said walls to compress said compressive member, a spider pivoted tosaid head piece, and a link operatively connecting said spider and the other arm of said bell crank wherebythe compressive force of said member resiliently resists tilting of said spider.

TOM ELLEMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,433,694 Atwood Oct. 31, 1922 2,909,018 Sengpiel May 16, 1933 2,321,385 Harold June 8, 1943 2,341,124 Sheldrick Feb. 8, 1944 ,354,736 Boerner Aug. 1, 1944 2,403,198 Sheldrick et a1 July 2, 1946 

